Garden tips – bad neighbors

I couldn't tell you why these particular vegetables and fruits make bad bedfellows but here is a list of things you might want to plant and the things you should not plant next to them:
Beans - onions, garlic, shallots, and leeks.
Beets - pole beens and mustards
Broccoli - strawberries and sunflowers
Cabbage - strawberries, sunflowers, and grapes
Carrots - dill
Corn - tomatoes and sunflowers
Eggplant - potatoes, tomatoes, and peppers
Garlic - beans and peas
Lettuce - cabbage family and sunflowers
Onions - beans and peas
Peas - onions, garlic, shallots, and leeks
Peppers - eggplant, tomatoes, potatoes, and fennel
Potatoes- eggplant, peppers, tomatoes, squash, pumpkins, and sunflowers.
Strawberries - members of the cabbage family
Tomatoes - corn, potatoes, peppers, and eggplant
EDIT:
a website for reference. Some of the reasons are because of spreading diseases and pests. If you break up the planting then there well be less of a chance of losing entire gardens. There are cross pollination issues also. This wasn't posted as a DO NOT PLANT TOGETHER AT ALL COSTS.. it was just a little garden tip. =D
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